(Another) Comet Lovejoy

Comet Lovejoy (C/2014 Q2) passes behind the fire lookout on Huckleberry Mountain

Okay, it doesn't get much easier than this one. For the next month or so, the newest Comet Lovejoy (C/2014 Q2) will be naked-eye visible in a good and dark, nighttime sky. And it's buzzing past Orion, probably the easiest constellation to find in winter. This one won't trail across the daytime sky, like some of the famous comets, but it's still worth the little bit of effort required. (Sky charts here.)

Currently, Lovejoy is sporting a fuzzy-green coma and, in really dark skies, a blueish tail. It will be challenging to see the comet's tail as our moon fattens towards full, on January 4th. But any old pair of binoculars will give you a great view of the coma, and dark skies will return as we head towards the next new moon, on January 20th.

I say "another" comet Lovejoy because this is the fifth such comet named for its discoverer, Australian astronomer Terry Lovejoy. But this particular comet Lovejoy only visits our neighborhood every 14,000 years or so, making it "new" to us. In other words, this is your best, worst, and only chance to see it.

Rock On, Geminid Meteors

Four Geminid meteors slice through the sky above weak northern lights, viewed over Lake McDonald,
in Glacier Park early Monday morning. The orange glow (bottom right) is light pollution from the lodge.

Our perennial winter clouds parted for one evening on Sunday night and Monday morning, just past the peak of our annual Geminid meteor shower. A good number of meteors still rained slowly down throughout the night, joined late by a little bit of green aurora glow. As comet-caused meteor showers go, the Geminids' source is far stranger than any comet we currently know of.

When the Geminid shower first appeared in 1862, it was weak with few "shooting stars." But it has grown in intensity ever since and is now one of our most prolific storms. The amount of debris left in the Geminid stream outweighs other meteor streams by 5X to 500X. Yet the source managed to evade our eyes and instruments for another 121 years.

Finally in 1983, the storm's brooding source was discovered and named "Phaethon" (after the underachieving son of "Helios," the Greek sun god). Phaethon is an asteroid-like object whose orbit takes it closer to the Sun than any other named asteroid - less than half the distance between Mars and the Sun. At its closest point Phaethon's surface reaches 1,400 degrees Fahrenheit (blazing when compared to Halley's maximum temperature of 135 degrees).

It was originally thought that, at such extreme temperatures, solar heating would blow and shake dusty debris off the asteroid's surface. Its passes near the Sun (every 17.5 months) have been carefully observed and analyzed since 2009, and indeed Phaethon doubles in brightness like a comet. But, surprisingly, the amount of debris blown off during each orbit only adds 0.01% to the mass of Geminid's debris stream. Phaethon does not kick up enough dust and gravel to keep the Geminid shower stocked with meteors.

Now we need new categories. Perhaps Phaethon is the remains of a nearly-dead comet. Its elliptical orbit and dark surface color are both comet-like. Maybe it's made enough trips around the Sun that it's been left parched and gravelly - at my age, I understand.

So what does all this ambiguity leave us? Introducing, "rock comet." As the lines blur between asteroids and comets, the idea of desiccated comets of rock and gravel is gaining ground. Rock on, Geminid mother, whatever you are.

Fiery Dust From a Famous Snowball

Orionid meteor and northern lights this morning over the Livingston Mountain Range, in Glacier National Park

Orionid meteor flying through its namesake constellation

Every time I climb in the truck and circle into town, I leave a few miles of gravely dust between home and the highway pavement.

Comets sorta' do the same thing.

Every time Halley's Comet makes its 76-year loop around the Sun, it leaves a trail of dust along the inner part of its elliptical orbit. As the comet reaches our inner solar system, the Sun heats and degrades this big, dirty snowball, causing it to drop debris along its path.

And every time the Earth makes its annual lap around the Sun, it flies through this narrow trail of comet dust in late October. Right now in fact. Some of the dust burns up in our atmosphere, causing the "falling stars" that we call the Orionid meteor shower. It should be called the "Halley's meteor shower," but it's called Orionid instead because most of these meteors appear to originate from the vicinity of the constellation Orion. These mostly-tiny particles hit the upper atmosphere about 60 miles above ground and burn up at a blazing 418 miles per hour.

One calculation I found estimates that Halley's Comet might loose an astonishing 6,283,174,472 tons each time it loops around the Sun. At this rate, with a 76-year orbit, Halley's Comet would make 95 laps over 7,220 years before completely disintegrating.

Halley's Comet last passed through the neighborhood in 1986 and won't return until July of 2061. But the comet's dusty trail is also the source of falling stars during the Eta Aquariids meteor shower, which takes place every May. Twice a year, Halley serves up two heavenly reminders of how amazing our little solar system really is - when we stop to look.

Great infographic on how comets and meteor showers are connected
A 500-pound meteorite from Halley's Comet fell on Texas in 1910

Or, another possible source for that beautiful shooting star you saw

Vega, A Rising Star Over Montana

The bright and occasional north star, Vega, sits low on the horizon and shimmers across a foggy
Lake McDonald between the dim winter Milky Way (left) and Comet Lovejoy (right). (Click to enlarge.)

On the rare cloudless night, thick blankets of stars warm our winter sky over western Montana - at least for those of us living beyond the shroud of city lights. And from lounging around summertime campfires we remember that the constellations seem to spin circles around the "north star," named Polaris, which though dim is still the brightest star in the Little Dipper constellation.

But Polaris isn't always our north star.

Polaris currently sits almost straight in line with the Earth's north-south axis of rotation. But the Earth isn't perfectly round, and gravity from the sun and moon pulls a little wobble into our spin. This wobble makes that imaginary point in the northern sky (the "north celestial pole") move in a giant circle lasting 25,765 years, a movement called the Earth's "precession." This means that over time the precession changes which star we perceive to be the north star. Several stars (and a whole lot of empty space) happen to fall along this circular path.

When a pinpoint of light arrives at the north celestial pole, and appears in the same place for many human generations, it is quite useful to the people living on this wobbly, spinning top. For our cave-dwelling ancestors 12,000 years ago, it was the bright star Vega that aligned as their north star. And in roughly 12,000 years from now, Vega will once again take its turn as our north star, passing within four degrees of the north celestial pole. Vega is more than twice as massive as our star, the Sun, and it is the second-brightest star visible from the northern hemisphere (after Arcturus).

The star we now know as Thuban served as the north star for the ancient engineers, who used Thuban to help them design and build Stonehenge and the Great Pyramids, roughly 4,000-2,700 years ago. Even though it's a dim star, Thuban sat precisely in the polar position in the year 2,787 B.C. And roughly 21,000 years from now, Thuban will once again reoccupy this prime spot in the night sky.

Our current navigational star, Polaris, is one of the dimmest stars that we can see with the naked eye. Polaris currently sits about 0.7 degrees off the celestial north pole, heading out on its long journey around the night sky. It'll complete its current lap in about 23,000 years. (Polaris is also the current pole star for Saturn, about 6 degrees off center.)

Down in the southern hemisphere, the south celestial pole currently falls in a dark region within the constellation Octans. The nearest stars are very faint, so the folks down under currently don't have a "south star." Just one more reason to spend a little time admiring the dark, star-lit skies over Montana, and anywhere else that the sky is still dark enough to contemplate the stars.

Celebrating Love, Joy, and Halley's Hope

(Extra-long edition covers multiple holidays...)


Comet Lovejoy rises over Glacier Park's Mt. Brown on Dec. 7th, 2013

Long ago, before the first Christmas as we now know it, good people of the northern hemisphere looked forward to a late-December celebration. Winter solstice, the shortest day of their year, was celebrated in myriad ways among countless cultures.

When the winter solstice fell on December 25th, in 274 AD, Roman Emporer Aurelian proclaimed the day as "Natalis Solis Invicti," the "festival of the birth of the invincible sun." Many years later, Christians would borrow this date for a new celebration of love, joy and hope.

This year, the winter solstice arrives today, December 21st. Four days before Christmas, two weeks after Hanukkah ended, and a month after the aptly-named "Black Friday." But so far this month, it has been Comet Lovejoy - not Santa Claus, Hanukkah Harry or Sam Walton - that has delivered excitement, inspiration and amazement the world over (unlike that Grinch, Comet ISON).

Lovejoy showed up unannounced in the middle of these celebrations. What about hope? Well, that's a different story. Hope takes us back a few decades, back to the 1910 return of Halley's Comet. But first, hope had to endure centuries of fear and ignorance - the twin currencies of soothsayers then and now.

Movements of the sun and moon were regular and predictable to even the earliest peoples, but comets appeared and disappeared without warning, which made comet sightings scary to some. Looking backwards in time, some people began to associate comets with any event that had also occurred at roughly the same time - a few peaceful events, but mostly destructive ones - casting comets as bad omens.

Admittedly, the science side of comets also got off to a rocky start with "Aristotle's Comet" in 372 BC (when the wise young Greek was but 12 years old), partly because the first telescopes were still 2000 years in the future. So as an adult, even Aristotle mistakenly described comets as Earthly gasses which, after rising to the upper atmosphere, were set afire by friction from the heavens revolving around us. A quick flame produced a shooting star, a slow flame produced a bright comet.

A set of Chinese silk paintings from 168 BC was a field guide to comet tails, identifying whether war, famine or death would soon follow. A comet appearance in 74 BC was later hitched to the fall of Jerusalem in 70 BC, four years after the comet passed. And 1st century Roman poet/astrologer, Marcus Manilius, wrote of comets in Astronomica (a single poem that filled five volumes), "Heaven in pity is sending upon Earth tokens of impending doom." It started sounding like the heavens were sending more doom than hope.

Halley's Comet in Gitto's "Adoration of the Magi"

Maybe the best, rare good omen was the return of Halley's Comet in 1301, serving as the inspiration behind a blend of religion and comet lore. In "Adoration of the Magi," the famous fresco completed in 1306 by Italian painter Giotto di Bondone, a comet replaces the Star of Bethlehem above the adorers who are kissing the feet of baby Jesus. In composing his version of the nativity scene, Gitto replaces the guiding angels with a comet. It stands well apart from other religious art masterpieces created in that time.

Returning to bad omens, two comets in 1664 and 1665 became superstitiously linked to the 1665 Black Plague of London (which actually originated in the Netherlands in the 1650's). That same year, an English astrologer published De Cometis, warning that, "These Blazeing Starrs! Threaten the World with Famine, Plague, & Warrs" [sic]. No doubt his book became a best-seller - at least among the frightened survivors.

How does this business of misinformation lead us to hope? Don't worry, we're getting there.

It began in 1682 when English astronomer Edmond Halley began studing the motion of comets, after witnessing two of them in person. Using a revolutionary new theory of gravity, from the "Philosophiæ Naturalis Principia Mathematica," published in 1687 by Sir Isaac Newton (following Halley's considerable encouragement and support), Halley predicted that this comet was the same one recorded in 1531 and 1607, and that it would return again in 1758. Unfortunately, Edmond Halley died in 1742. But in 1758, the comet re-appeared exactly as Halley had calculated - the date was Christmas Eve.

Haley's Comet only comes 'round once every 74 to 79 years (the timing gets altered by gravity from the planets it flies past). It's next appearance will occur on July 28th, 2061. Back in 240 BC, Chinese astronomers noted a bright comet, which is the earliest accepted record of what we now call Halley's Comet. Since then, this singular comet has been blamed for an astounding array of events.

The comet named after a brilliant scientist was also blamed by some people for the 79 AD eruption of Mount Vesuvius and the destruction of Italian city of Pompeii. His comet of 1066 was taken as a sign that the English would be defeated by invading Normans at the Battle of Hastings. And Halley's Comet in 1835 was especially busy, catching blame for the fall of the Alamo in Texas, a New York City fire that burned 530 buildings, and for starting wars in Cuba, Mexico, Ecuador, Central America, Peru, Argentina, and Bolivia!

In spite of so much superstition - and also because of it - the return of Halley's Comet in 1910 finally brought hope. Literally, at first.

Hope first arrived in pill form - specifically, "Hope's Anti-Comet Pills," which were advertised as, "An Elixir for Escaping the Wrath of the Heavens." Thousands were sold for 25 cents to one dollar apiece, depending on the customer's anxiety level. (The pills were a harmless combination of sugar and quinine.)

As Earth anxiously approached Halley's dusty trail in May of that year, the hucksters turned out in force. In addition to anti-comet pills, you could purchase lead umbrellas that would deflect deadly comet dust. Or you could rent a seat on a submarine that would remain safely submerged while everything on land was destroyed in a fiery inferno.

Or, if you lived in south Texas, you could buy comet-proof leather inhalers for between $2 and $24, sold by two busy entrepreneurs from Ohio. Both men were arrested for swindling, but the Brazoria County Courthouse was besieged by crowds of Texans who pleaded for the men to be released. Successful, some of these panicked people then purchased 50 inhalers at a time.

Churches were packed across the US. In Philadelphia, the Rev. Abraham Lincoln Johnson held a revival that reduced his congregation to a "paroxysm of fear" as he described the coming comet destruction. A California prospector nailed his own feet and one hand to a cross, then pleaded with his rescuers to leave him be. A Louisville newspaper reported on end-of-the-world preparations "through central and eastern parts of Kentucky."


Halley's 1910 Comet was the first one ever photographed

Around the world, the money changers profited from the many souls preparing for doomsday. And yet...

Among other parts of the populace, rooftop comet-viewing parties were lavishly arranged and heartily enjoyed because, as you may know, as the human race passed through the dust trail of Halley's Comet for six full hours, every person who had swallowed Hope Pills survived unscathed - and so did everyone else. Their celebrations were accompanied by dance music from a popular song sheet, the "Halley's Comet Rag," and comet post cards and souvenirs sold quite well in Paris.

Unlike earlier comet viewers, the good people of 1910 Earth had newspapers, telegraphs and telephones that quickly spread the lack-of-destruction news between distant lands. Hucksters made use of these new technologies, of course, but so did scientists and reporters. And in this way, an infant, world-wide public relations event was born. The fear mongers faded back into the shadows, and the big 1910 comet celebration turned into a public and scientific hit!

It was an educated man who predicted the "Broom Star's" return in 1910. It was men of reason who assured and reassured that the comet posed absolutely no threat to any Earthly life form. And it was a good portion of the general public who finally began putting their some of their faith into reason, probably for the first time ever on a world-wide basis. This was a huge victory for science, a slam-dunk defeat over the purveyors of fear and ignorance, and the good people took notice.

Reasoned hope was a true blessing that we received, belatedly, in 1910.

Widespread fear of comets disappeared for the rest of the 20th century. Unfortunately, like a scary-good zombie, a profitable business model is also hard to kill, regardless of the damage it may cause. And so fear is becoming a hot commodity once again. Fear can be a formidable foe, if you allow it, but reality is undefeated in the end. So whenever I hear these modern-day soothsayers (anti-vax, climate change deniers, etc.) selling fear, ignorance and hate as alternatives to love, joy and hope, I just smile and think to myself,

COMET PILLS !

Comet Lovejoy makes its closest approach to the sun tomorrow, December 22nd, and from there it will get slung back out into our night skies for a little while longer. This holiday season, I hope that you can take time to appreciate all manner of heavenly gifts that are offered. Happy belated Hanukkah, peaceful solstice, and merry Christmas!

COMET MUSIC: Even if there was more than one modern song written about comets (there isn't), my favorite would still be, "Halley Came to Jackson," written and performed by Mary Chapin Carpenter here. You can read all of the lyrics here.

Late one night when the wind was still, Daddy brought the baby to the window sill
To see a bit of heaven shoot across the sky, The one and only time Daddy saw it fly
It came from the east just as bright as a torch, The neighbors had a party on their porch
Daddy rocked the baby, Mother said "amen," When Halley came to visit in nineteen ten

 

(from "Halley Came to Jackson" by Mary Chapin Carpenter)

Comet Lovejoy on a Steamy December Night

Left to right: Chief Mountain, Comet Lovejoy, meteor smoke trail

Somehow I overlooked the forecast for record cold when I lined out the angles and cloud cover for a chance to see Comet Lovejoy setting over Chief Mountain. It was rather crisp (-15F/-26C) for photographing, and a little steam from the Saint Mary River (out of view in foreground) provided a wispy fog layer to shoot through. This was yesterday evening, and the lights of downtown Babb glowed in holiday shades of green and orange.

I had just sort of pointed my camera/tripod north and set the initial focus without looking through the lens, and was still fiddling with frozen thumbs when I caught sight of the meteor streaking in. I reached over and pressed the shutter only by instinct. At this point, I hadn't even had a chance to locate the comet with my binoculars, but my earlier calculations told me where it was supposed to be. Cross your fingers old fella'.

It almost never happens to me, but this time I got lucky. Comet Lovejoy rises parallel to the meteor's cursive smoke trail, and both point towards the majestic mountain. Try as I might, this is the closest alignment with Chief Mountain that I can manage without skiing miles into the backcountry and spending a few below-zero nights waiting for the mountain clouds to cooperate.

Comet Lovejoy (C/2013 R1) was only discovered a few months ago, on September 7th, and it's already passed by our little planet on its way towards a Christmas day perihelion with our neighborhood star, when it will loop around roughly 75.4 million miles from the sun. It should be somewhat visible through December, more or less, but it leaves us farther behind with each passing day. Don't worry, though, it'll be back in roughly 7,000 years.

Old vs. Ancient - The Blasdel Barn and Comet ISON

Comet ISON (upper left) rises before dawn falls upon the 1909 Blasdel Barn, near Kalispell (click to enlarge)

The old Blasdel Barn was raised in 1909 and is now listed in the National Register of Historic Places. Sunlight has faded its red paint to a memory, and lots of shingles and boards have fallen by the wayside over the years. This grand old barn has stood tall for 104 years, but it's very slowly falling apart.

On another scale - one that, I think, puts our human endeavors in their proper place - when this old barn was built, Comet ISON was already 4.6 billion year old, give or take. On its first and only trip through our solar system, ISON is on a slingshot course around our sun. If it survives today's encounter, it will be flung back out into deep space, never to return.

In the next 24 hours, ISON will skim a mere 700,000 miles above the solar surface - a distance that's less than the sun's diameter. An incredible amount of solar radiation is blasting and aging the comet quickly. From a rock/ice core that's just over one mile wide, ISON's ice is being vaporized into a fuzzy "coma" that's about 80,000 miles wide, with a tail of dust and vapor that's 5 million miles long, pushed away from the sun. One astronomer calculated that the sun is blowing away 3 tons of comet material per second.

As ISON passes the sun, it will reach a top speed of 225 miles per second, or more than 1500 times faster than a commercial jet, which would cross the U.S. in 15 seconds at that speed. I'm not quite sure if there's a way to calculate how this compares to the speed of the horse-drawn stage that used to pull into the oversized passage, through the heart of the Blasdel Barn.

Like the days of horse power, this comet encounter will soon pass and never come back 'round. Enjoy it while you can.

                     ----------------------------------------------------------------------------


Comes in as a comet (right), departs as a dust cloud (top).
SOHO Image by NASA (click for video)

UPDATE: Well I hope you got to see it in the pre-Thanksgiving, pre-dawn big sky, because Comet ISON is no more. Just prior to its closest approach to the sun ("perihelion") on November 28th, the indescribable heat and solar radiation ripped off the fuzzy coma and long tail, and nuked its nucleus into so many pieces. What emerged from the solar fire was a cloud of dust and small fragments. The glow from this cloud-of-dust-formerly-known-as-ISON is fading rapidly as it heads away from the sun. Unfortunately, instead of turning into the "Comet of the Century" as hoped, ISON's remnants will not even be visible to ground-based telescopes.

Highlights of Comet ISON from NASA Science News.
Text version can be read here.
ISON at perihelion